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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * This code is free software; you can redistribute it and/or modify it
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 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
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package com.oracle.svm.core.thread;

import jdk.graal.compiler.api.replacements.Fold;
import org.graalvm.nativeimage.ImageSingletons;
import org.graalvm.nativeimage.IsolateThread;

import com.oracle.svm.core.Uninterruptible;

/**
 * Support for getting thread execution time.
 */
public interface ThreadCpuTimeSupport {

    /**
     * Returns the current thread execution time.
     *
     * @param includeSystemTime if {@code true} includes both system and user time, if {@code false}
     *            returns user time.
     * @throws UnsupportedOperationException if OS specific implementation does not support given
     *             parameters.
     */
    @Uninterruptible(reason = "Called from uninterruptible code.", mayBeInlined = true)
    long getCurrentThreadCpuTime(boolean includeSystemTime);

    /**
     * Returns the thread CPU time.
     *
     * @param isolateThread the thread for which the information should be queried.
     * @param includeSystemTime if {@code true} includes both system and user time, if {@code false}
     *            returns user time.
     */
    @Uninterruptible(reason = "Called from uninterruptible code.", mayBeInlined = true)
    long getThreadCpuTime(IsolateThread isolateThread, boolean includeSystemTime);

    @Fold
    static ThreadCpuTimeSupport getInstance() {
        return ImageSingletons.lookup(ThreadCpuTimeSupport.class);
    }
}
